watson



(No Model.) 3 Sheets-Sheet 1 J. A. WATSON.

. VACUUM DBSPATGH SYSTEM. No. 574.965. Patented Jan. 12,1897.

3 Sheets-Sheet 2.

(no Moder.

J A. WATSON. VACUUM DESPATGH SYSTEM.

No. 574,965; Patented Jan. 12, I897.

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UNITED STATES PATENT OFFICE.

JAMES A. WATSON, OF IVASHINGTON, DISTRICT OF COLUMBIA.

VACUUM DESPATCH SYSTEM.

SPECIFICATION forming part of Letters Patent No. 574,965, dated January12, 1897.

Application filed February 18, 1893. Serial No. 462,901. (No model.)

To all whom it may concern.-

Be' it known that I, JAMES A. WATSON, a citizen of the United States,residing at Washington, in the District of Columbia, have inventedcertain new and useful Improvements in Vacuum Despatch Systems, of whichthe following is a specification.

This invention is denominated a vacuum despatch system.

The object of the invention is to provide means for the carriage of mailand express matter and light freight at a high rate of speed and with aminimum expenditure of power.

In the apparatus of the invention there is a tube which is closed at theends by suitable valves or gates and one or more air-exhaust pumps(arranged at regular intervals along the tube, when it is a long one)for exhausting the air from all portions of the tube and maintainingwithin it a vacuum as nearly perfect as is possible. At the initial endof the tube there is a lock-chamber, by means of which cars or carriersmay be inserted in the tube without permitting the atmospheric air toenter. Means are provided for pro pelling the carriers within the tube,the preferred means being electricity, and the preferred arrangementbeing to place the dynamos in the pumping-stations, so that they may beoperated from the same source of power as the pumps.

The invention further consists of the details of the lock-chambers andthe means for receiving and stopping the carriers at their destinations.

The term tube is used in this specification in a sense broad enough toinclude any hollow trunk, whether square, round, or of any othersection. The term vacuum will be understood to include the attenuated orrarefied atmospheres attainable with mechanical air-pumps, and the termcarrier, as used, will include any cars or conveyances adapted to travelwithin a tube.

I may propel the carriers within the vacuum-tubes by any suitable means,such as a cable, but I prefer electricity, and in the accompanyingdrawings I have illustrated two ways of propelling them by this form offorce.

Rapid transit for mail and express matter has been heretoforeaccomplished in one or the otherof two methods. One of these methods isto provide a railway with rails so placed as to prevent the car fromleaving them, and then to provide powerful motors, usually electrical,to force the cars forward at the highest practicable speed. \Vith thismethod a very high rate of speed cannot be attained for the reason thatthe resistance of the air to the movement of the car increases nearly asthe square of the speed of the car and becomes enormous for high speeds,thus rendering it costly to maintain a moderatelyhigh speed andimpossible to obtain as high a speed as is desirable. Thepneumatic-despatch tube is the other means of propelling cars orcarriers at a high rate of speed, but such tubes are not practicable forthe highest speeds or for long distances. The reason for this is that acolumn of air the length of the tube has to be propelled, as well as thecarriers within the tube. This air is propelled either by forcing it inat one end of the tube or exhausting it from the other end, or both. Ineither case the friction of the air upon the tube is very great andconsumes a large portion of the power.

Referring to the drawings, in which like parts are indicated by similarreference-signs throughout the several views, Figure l is a diagram of atube with the operating devices therefor, parts of the tube being brokenaway. Fig. 2 is an enlarged longitudinal section showing a portion ofthe tube and a carrier. Fig. 3 is a cross-section on the line 3 3 ofFig. 2. Fig. 4 is a sectional View similar to Fig. 3, showing a tubeprovided with a double track. Fig. 5 shows a diagrammatic view of a tubeprovided with different means of propulsion, and Fig. 6 is a sectionalview of a tube without internal rails and showing an end elevation of acarrier adapted to run in such a tube.

In the drawings, A A indicate tubes, B 13 indicate the air-pumps forexhausting the air from the tubes, and O 0 indicate dynamos forsupplying motive power to propel the carriers. I prefer to arrange thepower-stations at regular intervals along the line of the tube and toplace an air-pump in each power-station. These pumps may be operatedcontinuously or periodically, depending upon the amount of leakage ofair into the tubes.

tube.

With perfectly air-tight tubes very little pumping will be necessary.

In Figs. 1 and 5, A indicates the initial or starting end of the tube.This end, as shown, is provided with two valves, one at either end of alock-chamber, which permits the carrier D to be trapped into the tubewithout permitting the entrance of any but a small portion of air. Asshown, there is a valve 1 at the end of the tube which is pivoted at 2and provided with an operating-handle At a distance slightly greaterthan the length of the carrier from the end of the tube is a secondvalve 4:, which may be drawn up into a casing 5 by means of a hand-wheel6, attached to the screw-stem of the valve. Extending around the valve 4is a by-pass pipe 7, provided with a valve 8, said pipe forming acommunication between the lock-chamber and the vacuum-tube. Another pipeor port 9, controlled bya valve 10, forms a communication between theloclcchamber and the atmosphere.

In Figs. 1 and 5, A indicates the delivery end of a single-track tube.As illustrated, the end of the vacuum-tube is closed by a pair ofpivoted gates 11, which are arranged to open automatically upon thearrival of a carrier. The gates 11 are each provided with toothedquadrants 12, which are operated by racks 13, attached to the armature11 of a powerful electromagnet 15. Springs 16 are provided for closingthe gates, and they are held tightly closed normally by the atmosphericpressure. The circuit through the magnet is completed by the carrier, asit passes between terminals 17 before reaching the gates, the gates arein'nnediately opened, and the carrier passes out into an open tube 1!),which forms an air'cushion. The tube 19 may be of any suitable length,according to the speed at which carriers arrive. Its outer end is closedby a valve 20, and it is also preferably provided with a whistle 21 anda vent 22.

The operation of starting and stoppin g the carriers is performed asfollows: Referring to Fig. 1, the valves 1 and S are closed and thevalve 10 opened to admit air into the lockchamber and relieve theexternal pressure on the valve 1. The valve 1 is then opened and thecarrier D passed into the lock-chamber. The valves 1 and 10 are thenclosed. The carrier will have displaced most of the air in thelock-chamber, and the remaining air may be pumped out directly orpermitted to pass through the valve 1 when it is opened. In order torelieve the great pressure on the valve 1 before opening it, if the airhas not been pumped out of the lock-chamber, the valve 8 in the bypass 7may be opened, thus permitting the air to go into the vacuum- Thecarrier may then be started into the tube. \Vhen arriving at the otherend of the tube, the carrier strikes the contacts 17, and the gates 11are immediately opened by The carrier, traveling at a the magnet 15.

high velocity, passes through the gates 11 into the tube 19 and isgradually stopped by the resistance of the air in the tube. The gates 11are immediately closed by the springs 16. The compression of the airwill sound the whistle 21 and notify the attendant, so that the valve 20may be opened. The air-veut 22 should be large enough to prevent thecarrier from compressing the air to such an ex tent as to cause it torebound. Byinclining the tube 19 the carrier will run bygravity to theexit-valve 20. Y

In Figs. 1, 2, and 3the carrier is propelled by means of an electricmotor 23, the current coming from the dynamos C and passing through theinsulated rail M, the trolley wheel 25, the motor, the driving-wheel 26,and returning through the rail 27 or the tube itself. The motor, asshown, is connected to the driving-wheel by means of a belt 28 andpulley 29. In Fig. 5 the motive power is supplied through a series ofsolenoids 80, which are brought into action successively by the carrieritself, which closes the circuits between the contacts 31 and 32. Theabove methods of propelling carriers need not be more particularlydescribed, as they are common and well known to those skilled inelectricity. Many other ways of propelling carriers in vacuu1n-tubeswill suggest themselves. For distances of a few miles it may bedesirable to operate the carriers by gravity. This may be easilyaccomplished by running the starting end of the tube to the upper lloorof a high building or into a tower. A fall of two hundred and .iiftyfeet will give the carrier an initial velocity of about two miles perminute, and this velocity will carry it a long distance through thetube, as the resistance is very slight. In this way short lines ofdespatch-tubes in cities may be economically operated.

One advantage of myim proved system over pneumatic tubes is thatcarriers may be run in opposite directions in the same tube. For thisreason alarge tube may be erected, which will admit a workman for thepurpose of making repairs at about the same cost which it would take toconstruct two smaller tubes. A cross-section of such a tube is shown inFig. 4. Another advantage is that tubes intended for the passage ofsingle carriers may be formed with a perfectly smooth interior, leavingnothing to get out of order. Fig. 6 shows a cross-section of such a tubewith an end view of a carrier adapted to run in it. These carriers areprovided with three or more wheels at each end, so that it does notmatter which side of them is uppermost.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s-

1. In a despatch system, the combination of a normally closed andexhausted tube, a carrier movable within the tube, and exhaustingmechanism to constantly maintain a vac uum within the tube.

2. In a despatch system, the combination of a normally closed andexhausted tube, a carrier movable within the tube, and means forpropelling the carrier within the tube.

3. In a despatch system, the combination of a normally closed andexhausted tube, a carrier movable within said tube, a motor upon thecarrier, and means for supplying power to the motor.

4. In a despatch system, the combination with a normally closed andexhausted tube, and exhausting mechanism to constantly maintain a vacuumtherein, of a lock-chamber having suitable valves to seal the main tubeagainst the inflow of air while a carrier is being introduced.

5. In a despatch system, the combinationofanormally-exhausteddespatch-tube,means for maintaining the tube in anexhausted condition, a carrier movable within the tube, suitable valvesthrough which the carrier may be passed into and out of the tube, andmeans for propelling the carrier within the tube.

6. In a despatch system the combination with a normally closed andexhausted tube and a carrier movable therein, of a lockchamber at theinitial end thereof adapted to be closed air-tight, a valve forcontrolling communication between the lock-chamber and the tube proper,a second valve for controlling communication between the lockchamber andthe atmosphere, said lock-chamber being preferably but little largerthan said carrier, whereby the carrier may be introduced into the tubeWithout impairing the vacuum in the latter, substantially as described.

7. In a despatch system, the combination with a normally-closed andexhausted tube and a carrier movable therein, of a lock-chamberseparated from the exhausted portion by a valve, an entrance-valve atthe outer end of the lock-chamber, and means for alternately filling thelock-chamber with air and exhausting the same, to facilitate the operation of the valves, substantially as described.

8. In a despatch system, the combination with a normally-closed andexhausted tube, of

a lock-chamber separated from the exhausted portion of the tube by avalve, a valved bypass pipe around the said valve, an entrancevalve atthe outer end of the lock-chamber, and a valved port communicatingbetween the lock-chamber and the atmosphere, substantially as described.

9. In a despatch system, the combination of a normally-closed andexhausted tube, a carrier movable therein, and a tube 19 having itsouter end normally closed and its inner end open to the atmosphere andin line with the exhausted tube, said tube 19 being arranged to receivethe carrier from the exhausted tube and form an air-cushion for thesame, substantially as described.

10. In a despatch system the combination of a normally-closed andexhausted tube having two or more separate tracks or guideways therein,carriers movable within the tube and adapted to said tracks, and meansfor propelling said carriers in opposite directions at the same time,substantially as described.

11. In a despatch system,the combination of a normally-closed andexhausted tube, a carrier movable within said tube, and a series ofexhaust-pu mps in communication with said tube, said pumps beingarranged at intervals along the line of the tube, whereby any air due toleakage may be removed without creating detrimental air-currents,substantially as described.

12. In a despatch system, the combination ofv a normally-closed andexhausted tube, carriers movable within said tube, electromotors foroperating the carriers, and a series of power-stations arranged atintervals along the tube, each station being provided withdynamo-electric machinery and air-exhaust pumps connected with the tubefor supplying power to the carriers and exhausting the air from saidtube respectively, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

7 JAMES A. WATSON.

Witnesses:

WILL E. NEFF, W. CLARENCE DUVALL.

